Warewashing method using a cleaning composition containing low levels of surfactant

Abstract

Disclosed is a method of washing ware in an automatic institutional warewashing machine wherein the method includes contacting ware with a cleaning composition containing a surfactant and further includes contacting the washed ware in a rinse step with a potable aqueous rinse, the aqueous rinse being substantially free of an intentionally added rinse agent. A surfactant is employed in the wash step in an amount not to exceed 15 wt % based on weight of the detergent. The amount of surfactant is sufficient to provide a layer of surfactant on the ware so as to afford a sheeting action in an aqueous rinse step without any added rinse agent.

The invention claimed is: 
     
       1. A method of washing ware using a cleaning composition containing a surfactant, the method comprising:
 (a) contacting ware in a washing step with an aqueous cleaning composition in an automatic institutional warewashing machine configured so that no carryover of the aqueous cleaning composition from the washing step into a rinse step occurs, the aqueous cleaning composition consisting of a major portion of water and about 200 to 5000 parts by weight of a warewashing detergent per each one million parts of the water; and 
 (b) contacting the washed ware in a rinse step with a potable aqueous rinse, the aqueous rinse being substantially free of an intentionally added rinse agent, 
 wherein the warewashing detergent contains a sufficient amount of a surfactant to provide a layer of the surfactant on the ware so as to afford sheeting action in the potable aqueous rinse step, 
 wherein the method does not comprise a rinse step with a composition comprising an intentionally added rinse agent, 
 further wherein the aqueous cleaning composition from the washing step does not carry over into the rinse step, 
 further wherein the detergent is in the form of a solid, 
 further wherein the detergent consists of the surfactant, at least one builder material, at least one caustic agent, at least one flow control agent, at least one antiscalant, optionally, at least one antifoam, and optionally, at least one bleach, 
 further wherein the surfactant is present in an amount not to exceed 10 wt %, 
 and further wherein the surfactant present in the detergent and the aqueous cleaning composition is selected from the group consisting of a hydrophobically modified polysaccharide, a maleic acid/olefin copolymer, and a maleic acid/olefin copolymer combined with a polypropoxylate. 
 
     
     
       2. The method of  claim 1  wherein the surfactant provides an improved drying behaviour corresponding to the ratio of drying time using detergent with surfactant to drying time using detergent without surfactant being equal to or lower than 0.9. 
     
     
       3. The method of  claim 1  wherein the surfactant is present in an amount not to exceed 7 wt-%. 
     
     
       4. The method of  claim 1  wherein the automatic institutional warewashing machine is a single-tank machine or a multi-tank machine. 
     
     
       5. The method of  claim 1  wherein the surfactant is selected from the group consisting of the maleic acid/olefin copolymer and the maleic acid/olefin copolymer combined with the polypropoxylate. 
     
     
       6. The method of  claim 5  wherein the maleic acid/olefin copolymer has the formula 
       
         
           
           
               
               
           
         
         wherein L 1  is selected from the group consisting of hydrogen, ammonium, and an alkali metal; further wherein R 1 , R 2 , R 3 , and R 4  are each independently selected from the group consisting of hydrogen and an alkyl group containing from 1 to 8 carbon atoms; further wherein the ratio of x to y is from about 1:5 to about 5:1; and further wherein the maleic acid/olefin copolymer is characterized by an average molecular weight of about 20,000 or less. 
       
     
     
       7. The method of  claim 5  wherein the maleic acid/olefin copolymer has the formula 
       
         
           
           
               
               
           
         
         wherein L 1  is hydrogen or sodium, R 1  and R 3  are hydrogen, R 2  is methyl, R 4  is neopentyl, the ratio of x to y is about 1:1, and the maleic acid/olefin copolymer is characterized by an average molecular weight of about 12,000. 
       
     
     
       8. The method of  claim 7  wherein the maleic acid/olefin copolymer is combined with calcium ions or magnesium ions or both. 
     
     
       9. The method of  claim 8  wherein the surfactant is the maleic acid/olefin copolymer combined with the polypropoxylate. 
     
     
       10. The method of  claim 1 , wherein the detergent consists of the surfactant, the at least one builder material, the at least one caustic agent, the at least one flow control agent, the at least one antiscalant, the at least one antifoam, and the at least one bleach. 
     
     
       11. A method of washing ware using a cleaning composition containing a surfactant, the method comprising:
 (a) contacting ware in a washing step with an aqueous cleaning composition in an automatic institutional warewashing machine configured so that no carryover of the aqueous cleaning composition from the washing step into a rinse step occurs, the aqueous cleaning composition consisting of a major portion of water and about 200 to 5000 parts by weight of a warewashing detergent per each one million parts of the water; and 
 (b) contacting the washed ware in a rinse step with a potable aqueous rinse, the aqueous rinse being substantially free of an intentionally added rinse agent, 
 wherein the warewashing detergent contains a sufficient amount of a surfactant to provide a layer of the surfactant on the ware so as to afford sheeting action in the potable aqueous rinse step, 
 wherein the method does not comprise a rinse step with a composition comprising an intentionally added rinse agent, 
 further wherein the aqueous cleaning composition from the washing step does not carry over into the rinse step, 
 further wherein the detergent consists of the surfactant, at least one builder material, at least one caustic agent, at least one flow control agent, at least one antiscalant, optionally, at least one antifoam, and optionally, at least one bleach, 
 further wherein the surfactant is present in an amount not to exceed 10 wt %, 
 and further wherein the surfactant present in the detergent and the aqueous cleaning composition is selected from the group consisting of a hydrophobically modified polysaccharide, a maleic acid/olefin copolymer, and a maleic acid/olefin copolymer combined with a polypropoxylate. 
 
     
     
       12. The method of  claim 11  wherein the surfactant is selected from the group consisting of the maleic acid/olefin copolymer and the maleic acid/olefin copolymer combined with the polypropoxylate. 
     
     
       13. The method of  claim 12  wherein the maleic acid/olefin copolymer has the formula 
       
         
           
           
               
               
           
         
         wherein L 1  is selected from the group consisting of hydrogen, ammonium, and an alkali metal; further wherein R 1 , R 2 , R 3 , and R 4  are each independently selected from the group consisting of hydrogen and an alkyl group containing from 1 to 8 carbon atoms; further wherein the ratio of x to y is from about 1:5 to about 5:1; and further wherein the maleic acid/olefin copolymer is characterized by an average molecular weight of about 20,000 or less. 
       
     
     
       14. The method of  claim 12  wherein the maleic acid/olefin copolymer has the formula 
       
         
           
           
               
               
           
         
         wherein L 1  is hydrogen or sodium, R 1  and R 3  are hydrogen, R 2  is methyl, R 4  is neopentyl, the ratio of x to y is about 1:1, and the maleic acid/olefin copolymer is characterized by an average molecular weight of about 12,000. 
       
     
     
       15. The method of  claim 14  wherein the maleic acid/olefin copolymer is combined with calcium ions or magnesium ions or both. 
     
     
       16. The method of  claim 15  wherein the surfactant is the maleic acid/olefin copolymer combined with the polypropoxylate. 
     
     
       17. The method of  claim 11 , wherein the detergent consists of the surfactant, the at least one builder material, the at least one caustic agent, the at least one flow control agent, the at least one antiscalant, the at least one antifoam, and the at least one bleach. 
     
     
       18. The method of  claim 11  wherein the automatic institutional warewashing machine is a single-tank machine or a multi-tank machine.